Fish egg hatching device



Sept. 23, 1-952 R WEERT 2,611,337

FISH EGG HATCHING DEVICE Filed April 5, 1950 www@ /4 Har/v ry PatentedSept. 23, 1952 FISH EGG HAToniNG `DEVICE, 'A Richard Vibert, OloronSainte-Marie, France Application' April 5, 1950, Serial No. 154,082 Z InFrance April21, 1949 My invention is concerned with `a method of'-restocking streams with trouts, salmons and other fishes having similarbreeding habits which consists in imitating natural conditions asclosely as possible. y v I One is aware that the egg once impregnatedwill ony remain transportable for a comparatively short time (one day)after which it'must be allowed to rest until the'embryo is'formedwhereas once the embryo is formed in the egg the latter' istransportable on condition that it is kept moist and cool.

It is common practice to gather the eggs of sexually mature females,whether wild or bred, and to spray them with a milt of males. Theimpregnated eggs thus obtained are washed and laid in tray-likeincubators arranged in vats supplied with running water; Every secondorat the most third day it is necessary to remove the dead eggs thathave got whitsh, for Want of which the latter `are attacked by mouldwhich contaminates the neighboring ones. As a consequence of theaforesaid'necessity'only a thin layer of eggs can be accommodated'in theincubator.

After a time which is variable depending onj the' species and thetemperature of the water the fry hatches and their bags are resorbedprogressively. Not long before the resorption is completed it becomesnecessary to begin with the nursing of the fry with such a food as vealspleen or liver, yolk, curd, and so on, all of which are costly alimentswhich cannot be obtained in largel amounts.

The fry may be set free as soon as the bag is resorbed or later ondepending on the peculiarities of the river, the site and the foodavailable.

It is conveyed to the dumping places in large cans on a small truck orin hilly regions on mule back; however, if more than ten to twentythousands fry are to be dealt with it is advisable to provide ones selfwith oxygen cylinders and diusors. The fry must be cast at a great manydifferent places and each time in a very small number of individuals.

The necessity of satisfying all these requirements leads to considerablelabour costs and to the obtainment of usually underfed fry which inaddition is cast in frequently unfavorable conditions, so thatdissappointing results are obtained; in addition, the said necessityinvolves the existence of costly piscicultural establishments whichobviously cannot be installed in the neighborhood of every stream to berestocked.

These inconveniences have already incited several inventors to designportable incubators.

. s claims. (o1. 119-3) Thus, as such, a X50 X 15 cm. flat zinc boX hasbeen proposed having perforated sides. The eggs are laid in a thin layeron the bottom of the box and saine issunk to the bottom of the river.Following the resorption of the sack the fry get out by themselvesthrough the perforations inl the 'box sides. However, such a box isbulky and fewl eggs can be deposited therein as compared to itssize; itrequiresv at least a minimum of attendance'and cannot be allowed to getlost.

A further incubator is also known which consists of aj 16 X721 X3 cm.honeycomb. lThe two larger vfaces r'are' covered kwith a vclosely wovenmetal gauze. `It comprises 500 cells each of which contains one egg.Onceloadedthe incubator suspended in the river at the proper'places; thedead eggsV cannot contaminate the'gsound ones since each eggis isolatedin its cell. Such an incubator requires atleast a minimum of attendancetogether with the cleaning of the Wire gauzerfrom timer to time and the'opening of the cover at the "right time in ordertoliberate the f ry.'TheA said apparatus has beenl used rprac-v gravel and'sand.y Saideggs'are by 'nomeans scattered; they are rather gathered in cavitiesbetween the pebble stones, in which cavities the dead eggs will notcontaminate the sound ones, a consequence of the fact that theincubation process goes on completely in the dark.

Consequently, the method according to my invention consists in arrangingtrout or salmon eggs, Whether only milted or in which the embryo isalready formed, in packing boxes suitable for the transportation of theeggs and provided with apertures of such size that the fry and not theeggs can get out of them. The eggs may be dispatched by the supplier asusual in trays with a fabric bottom on which the eggs are arranged andwhich are piled up with a provision of ice in the topmost one, the wholepile is wrapped in strong paper and carefully heat-insulated in a boxwith sawdust or Wood Wool. The consignee then needs only to unpack thetrays, to load his own :fry-breeding boxes with eggs and to place themin an ordinary fishing basket packed with moist rnoss for theirtransportation to the places to be restored. O-r the fry breeding boxesacloaded by the consignor. In this case, the boxes ,aortic-EI] 3themselves are piled up instead of the trays and covered with ice. Theconsignes then needs only to take out the breeding boxes and to bringthem to the desired places.

At each restocking place known to be also natural spawning places thebottom is stirred to eliminate the mud and the exceedingly ne vsand asdo the shes themselves and the boxes are immersed and `e mbedded in thegravel. The 'results obtained with the packing and breeding boxesaccording to the invention are comparable, fas lto the number ofindividuals having resorbed their sacks, liberated and acclimatized tothe partic'ular river, to those obtained with compari'- son lotsobtained :by pisciculture before the fry is dumped and consequentlyb'eforethe acclima- (tizatioI-i crisis, th'e individuals moreover being'about 15% heavier.

Practically, breeding boxes of preferably rectangular parallelepipedalshape should be used .for the sake of convenience in the storing of theempty boxes and the packing of the loaded ones.

For the purpose of exemplication and by no means of limitation aparallelepiped'al box l is illustrated in perspective View in theappended drawing. The box I has a top and bottom 2, side walls 3,'and ismade of a transparent plastic material and is provided with oblongorices 6 (e. g. 6 mm. in width for salmon) adapted to retain the eggswhile allowing the fry to escape even with their still unresorbed sacks,i. e. the orifices are of a Width which is slightly less than thediameters or' the spherical eggs but greater than the smallest dimensionof the fry which hatch from the eggs. In this manner it is possible totransfer the eggs from the production centres to their natural abodeamongst the pebble stones, gravel and sand of the streams to beresto'cked with no more manipulations than shipping the boxes andembedding the same.

What I claim is:

l. A device for transporting spherical fish eggs and effecting thedirect hatching thereof in their natural environment under conditionsclosely simulating natural hatching, which comprises a closed containerhaving atop, a bottom and side walls, said container being adapted toreceive said spherical eggs and to be embedded in gravelly river bottomsnormally utilized as spawn# ing-grounds by wild breeders, and at leastthe side walls of said container being provided with 4 a plurality ofspaced spertures having a width slightly less than the diameter of saideggs but greater than the smallest dimension of the fry which hatch fromsaid eggs.

2. A device for transporting spherical iish eggs and eecting the directhatching thereof in their natural environment under conditions closelysimulating natural hatching which comprises a closed container having atop, a bottom and side walls, said container being adapted to receivesaid spherical eggs and to be embedded in gravelly river bottomsnormally utilized as spawninggrounds by wild breeders, the walls of saidcontainer having a vstrength sufficient to withstand deformation whensaid container is stacked with a plurality of like containers and whensaid container is embedded in the river bottom, and at least the sidewalls of said container being provided with a plurality of spaced oblongapertures having a width slightly less than the diameter of said eggsbut greater than the smallest dimension of the fry which hatch from saideggs.

3. A device for transporting spherical fish eggs and effecting thedirect hatching thereof in their natural environment under conditionsclosely simulating natural hatching which comprises a closedparallelepipedal container having a top, a bottom and side walls formedfrom transparent material, said container being adapted to receive saidspherical eggs and to be embedded in gravelly river bottoms normallyutilized as spawninggrounds by wild breeders, and at least the sidewalls of said container being provided with a plurality of spaced oblongapertures having a width slightly less than the diameter of said eggsbut greater than the smallest dimension of the fry which hatch from saideggs.

RICHARD VIBERT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Austria July l0, 1913

